Glenrock is probably abt the best there is, and their prices are stunningly reasonable.
What Steve said:
I have restored/reconditioned a lot of old guns: rust bluing and browning. You can do it, buuuut ... it takes cleanliness, space, equipment, time, cleanliness, chemicals, distilled water, cleanliness, time, cleanliness.
Johnny, 44/40 is the very best quick & dirty browner (I've never gone to blue with it) I have ever used. If you rinse it with dilute soda, it helps, but the very best final coating and rust-kill is beeswax.
Bob